1. Field of Invention
This invention pertains to a novel abrasion assembly, and more particularly, to a abrasion assembly formed of an abrasion plate resting on the railroad tie and a pad on the plate and supporting the rail. More specifically, means are provided to interlock the abrasion plate and the pad to resist being separated by the shifting of the rail laterally or longitudinally, and to lock the abrasion plate to the tie for shipping. Means are also provided to seal the underside of the plate from contaminate egress.
2. Description of the Prior Art
During the last decades, the old wooden ties used to support railroad rails were replaced by concrete ties and pads were provided between the rails and the concrete ties. These pads provided two functions: they acted as shock absorbers for the rails and they provided electrical insulation. This latter function is important for railroad systems in which the rails form a part of the electrical circuitry for either the motive power, signaling or control functions. Separate rail clips or other similar fasteners are used to clamp the rail to the ties. For example, commonly owned U.S. Pat. No. 5,110,046, incorporated herein by reference, discloses a two part abrasion assembly: an elastomeric pad and an abrasion plate resting on the tie. The abrasion plate was made of a heat treated high carbon steel. The abrasion plate was provided on its bottom surface with a layer of adhesive to secure it to the concrete tie. Other abrasion assemblies have been developed with an abrasion plate made of a plastic material.
However, problems still remain with abrasion assemblies. One problem is that, after excessive use, the concrete tie under the assembly gets worn and has to be repaired. A further problem is that over time rails tend to expand and contract longitudinally due to temperature changes, as a result of train movement and tie maintenance. This action tends to separate the two parts of the assembly.